What genetic tests are recommended in azoospermia?

[Verified against AUA/ASRM Male Infertility Guideline 2021] Karyotype and Y-chromosome microdeletion analysis should be recommended for men with primary infertility and azoospermia, or severe oligozoospermia under 5 million/mL, with elevated FSH, testicular atrophy, or a presumed diagnosis of impaired sperm production (Expert Opinion). Why the microdeletion result changes management, not just counselling: AZFc deletion — sperm may be found in the ejaculate in some men, and retrieved by TESE in at least 50%. Complete AZFa and/or AZFb deletion — sperm have NOT been retrieved by testicular sperm extraction in these men. The guideline states surgical intervention is not indicated. Offering micro-TESE here subjects a man to an operation with no realistic prospect of success. That single distinction is the strongest argument for testing before offering surgery rather than after. Karyotype: the commonest abnormality is Klinefelter syndrome. Rare foci of spermatogenesis are found on micro-TESE in at least 50–60% of 47,XXY men, so Klinefelter is not a contraindication to retrieval — the opposite of the AZFa/AZFb situation. CFTR: clinicians should recommend CFTR mutation carrier testing, including assessment of the 5T allele, in men with vasal agenesis or idiopathic obstructive azoospermia (Expert Opinion). Where a CFTR mutation is found, genetic evaluation of the female partner should be recommended (Expert Opinion) — this is about the offspring, not the man's fertility. Also worth knowing: diagnostic testicular biopsy should not routinely be performed to differentiate obstructive from non-obstructive azoospermia (Expert Opinion). History, examination, semen volume and FSH usually suffice.